In general vehicles, in order to heat the interior of the vehicles, dehumidify or defrost a front window of the vehicles, a heating system using heat energy of coolant heated by engine is installed therein.
In the case of this heating system, since the coolant flowing around the engine is introduced into a heater after the engine is operated, it should be time consuming to heat the interior after the coolant is heated. Therefore, after starting the engine, a driver must wait in cold for an interval long enough to heat the interior.
Meanwhile, Korean Utility Model Publication No. 20-144945 discloses a preheating system using a PTC (positive temperature coefficient) element in order to solve the problems. A structure of the preheating system will be described as follows.
As shown in FIG. 1, in an heater for vehicles including a plurality of PTC elements 20 for generating heat by supplying power, a plurality of isolation members 13 having through-holes for receiving the PTC elements are installed in a frame 11 in parallel with each other, a plurality of radiator fins 15 are installed between the respective isolation members 13 to facilitate a heat exchange, terminals (for example, negative terminals) at one side of each PTC element are integrated as one member to be connected to a power source, and terminals (for example, positive terminals) at the other side of each PTC element are connected to the power source through the medium of individually operating switches (not shown).
In addition, plates 17 and 18 are disposed between the isolation members 13 and the radiator fins 15.
In this connection, a reference numeral“19” designates terminal plates installed at front and rear sides of the frame 11, one end of the plate 17 is connected to the terminal plate to form one negative terminal together with the frame, and one end of the plate 18 is connected to a wire (not shown) to form one positive terminal, respectively.
In the aforementioned conventional pre-heater for vehicles, since components constituting the pre-heater are not modulized, assembly operations should be individually performed, thereby lowering productivity and operation performance.